There are many times in life when not all of the information is known. In math, we represent those unknown values as variables. The videos in this lesson will be a series that will teach you, step by step, how to solve for variables in equations. Remember, the = sign means that each side is equal to the other. Anything you change on one side must be changed on the other, or they will no longer be equal. Here are some math vocabulary words that will help you to understand this lesson better:

- Variable = a letter in an equation that represents an unknown value
- Additive Inverse = The number when added to another number equals zero
- Isolate = To get the variable alone

The following video will show you how to begin solving for variables.

Video Source (06:49 mins) | Transcript

The goal when finding a variable is to isolate it (or get it by itself) in the equation. To get rid of any addition or subtraction is to add the additive inverse of whatever is being added or subtracted. This step must be done to both sides of the equation for it to stay equal.

## Additional Resources

- Khan Academy: What is a Variable? (03:17 mins, Transcript)
- Khan Academy: Inverse Property of Addition (02:59 mins, Transcript)
- Khan Academy: One-step Add. & Subtraction Equations (02:08 mins, Transcript)
- Khan Academy: Same Thing to Both Sides (02:31 mins, Transcript)

### Practice Problems

**Solve for the variable:**

- \(n−4=14\) (Solution
- \(12+D=−6\) (Video Solution
- \(14=y−10\) (Solution
- \(F+19=1\) (Solution
- \(−10=J+30\) (Solution
- \(7=B−3\) (Video Solution
- \(-30+Y=40\) (Solution

**Need More Help?**

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